hello,
since cv can be used to modulate the frequency of the osc´s, i wonder if fm synthesis
would be possible my feeding an external osc´s signal into the a4.
anyone here tried this and can report about the results in comparison with using the internal lfo´s.
thanks, johannes
I don’t think that works
Maybe…just maybe…
On the mk2 you can send cv in to adjust any 5 parameters…
That’s a good point…I don’t know…
Since i dont own a a4 yet, it would be great if someone with a a4 could give this a try.
@Unifono: you mean the osc´s frequency can not be selected as a destination in cv menue?
I can’t imagine any scenario where this would be possible.
The A4 mk1 has only cv outputs.
It has an Audio in, but there is no way to route the audio from the in to the pitch of an internal oscillator.
You can use the Audio in as the waveform for one oscillator but there are no frequency modulation options between the two oscillators. Frequency and pitch modulation destinations are only given for the lfos and envelopes.
So fm is only possible via an audio rate lfo.
Somebody may correct me if I’m wrong
Edit: I can’t speak for the A4 mk2
The A4 mk2 has two cv inputs.
Can Someone with an mk2 please confirm that osc freq or pitch is listed as a destination for cv mod?
Sorry, thought you ask for the mk1.
That would be an interesting feature if it can be done in the mk2
nevermind, i didn’t made it clear in my question nor in the thread name… just edit it
Looks like it’s possible, but I haven’t tried yet.
Will report later.
Would be good to know if > 5v will damage A4.
great! thanks for give it a try @GiacomoB . looking forward to hear the results.
if this works as expected than one could achieve simple 4 op fm. basically a 2 pair (carrier, modulator) fm:
feeding 2 sine waves into the a4 via cv input 1 + 2. while input 1 mods osc 1 and input 2 mods osc 2 frequency.
and in addition one could use the lfo…
regarding cv input the manual says:
EXP/CV inputs
Input voltage on tip: -5 V–+5 V. Supplies +5 V on ring Accepts CV, Expression pedals
i think you can limit the range/amplitude of the cv-in-signal @ the cv menue of the a4 mk2…
Yes, it works.
I made just a simple test, but it’s enough to see that this will work.
Just how useful it might be depends on what you want to do. For example, keeping a constant ratio between modulator and carrier…hmm. Use a CV track out to modulator osc?
That adjustment sets the range of the input signal that corresponds to max and min modulation; looks like it’s mostly for allowing both unipolar and bipolar signals to work. But it’s not clear what might happen if the input voltage is outside that range.
You can send the cv through a vca first to be safe, but it would be nice to know if that’s unnecessary.
I’ll ask Elektron.
Cool. I already asked this elektron and waiting for reply.
Right, the lack of an constant ratio will make it hard to do harmonic fm spectra while changing the modfreq or the carrier base freq. anyway, this is no fm synth but beside am we could use fm technics to create complex spectras.
Like you i also had in mind to use a4 mk2s cv out signal and feed it back into cv in to mod the osc freq… Is that possible? I mean can i route an a4 mk2 osc to an cv?
Btw. Is there a noticeable between cv and lfo as the modulator? The higher Modulator Speed when using cv signal should definitely make a difference, right?
I would imagine Elektron have put limiters on the CV inputs because they know people will try plugging anything they can in. For FM, I’d be more concerned about sample rate and slew - remember that these inputs are run through an ADC, so the quality and reliability of FM will depend on that
Right, i asked elektron for limitation when using the cv input for fm. Lets see what they say… I Will report
I have tried it but the adc is to slow at audiorates.
Ah. Thanks.
I didn’t get that far.
And didn’t know about the AD conversion there. Too bad.
So it wont work for freqs higher than 16 hz? So than the lfo is faster than the adc…
I would have been really surprised if the CV input could handle audio rates
Copy-Paste from here :
http://patcharena.com/synth-resources/elektron-analog-four/
Sine Kick Using CV Track
ANSELMI from the Elektron-Users forum discovered this little trick using the Elektron Analog 4. A great use of the CV track if you aren’t using it on any external devices.
“This kick is generated by using the LFOs of the CV track as well as one CV output
You know, LFOs can go fast and since they got sine wave and you can make it reset at each trigger you can get a solid boomy kick out of them.
Just go to LFO1, set it at a speed that you can hear, then choose CV value as destination and then use the second LFO to modulate LFO1´s speed (pitch) with an expo decaying wave in “one” mode
then you can use ENV2 to shape the amplitude of your kick…or just the fade out parameter of LFO1 (much less accurate though) or a combination
of course it´s not for kicks only, you can make a lot of stuff with the LFO1´s waves…metallic FM tones, lo-fi noise stuff, sine bass, you name it
although LFO1 is fast enough to actually be heard it doesn´t have the quality of the proper oscillators, and it´s digital, not analog
anyway with some tweaking and p-locks you can get another track of sound just sacrificing one CV channel
and if you don´t want to mix it externally just plug it again into one of the audio inputs!”
That’s in regard to the CV outputs. The OP’s question is in regard to the CV inputs
